For seminars and other local announcements, please subscribe to sfu-cosmo mailing list.
Wednesday, 4 October 2006, 12:45 in P8445A
Dr. Serge Winitzki (Ludwig Maximilians University, Munich)
Predictions in eternally inflating universe
In generic models of cosmological inflation, quantum fluctuations strongly influence the spacetime metric and produce infinitely many regions where the end of inflation (reheating) is delayed until arbitrarily late times. The geometry of the resulting spacetime is highly inhomogeneous on scales of many Hubble sizes. The recently developed string-theoretic picture of the "landscape" presents a similar structure, where an infinite number of de Sitter and anti-de Sitter universes are nucleated via gravitational quantum tunneling. Since observers on the Earth have no information about their position within the eternally inflating landscape, the main question in this context is to obtain statistical predictions for quantities observed at a random location within the landscape. I describe the problems arising within this statistical framework, in particular, the need for a volume cut-off and the dependence of certain cut-off schemes on time slicing and on the initial conditions. I review the existing proposals for extracting predictions and give examples of their applications, in particular, to the cosmological constant problem.
Seminars in 2006:
[ See complete seminar archives | iCal feed ]
Modified by Andrei Frolov <frolov@sfu.ca> on 2023-11-01